Gaseous electric discharge device



Feb. 5,' 1935. R. DELAS GASEOUS ELECTRIC DISCHARGE DEVICE 2 Sheets-Sheet1 Filed Oct. 18, 1932 a M e D .Y B E m m L T e H mn Feb. 5, 1935.

R. L. DELAS 1,990,169

GASEOUS ELECTRIC DISCHARGE DEVICE 2 Sheets-Sheet 2 Filed Oct. 18, 1932INVENTOR er-1e Louis Delas,

BY Mala ATTORNEY Patented Feb. 5, 1935 UNITED STATES 1,999,169 GASEOUSELECTRIC DISCHARGE DEVICE Rene Louis Delas, Courbevoie, France, assignorto General Electric Company, a corporation of New York Applicationoctober 1a, 1932, Serial No. 638,408 In France October 29, 1931 4Claims.

, The present invention relates to gaseous electric discharge devicesgenerally and more particularly the invention relates to such deviceshaving thermionic electrodes.

-It is known in the art that a higher voltage is required to establishthe gaseous electric discharge in such devices than is necessary tomaintain said discharge after it has been established. For this reasonsuch devices have heretofore been connected to transformers adapted tosupply the necessary starting voltage and have been connected in serieswith a resistance or reactance adapted to dissipate the excess voltageduring the operation of the device.

Circuits have been proposed wherein the energy formerly dissipated inthe resistances or reactances has been utilized in heating thethermionic electrodes. Such circuits have, among others, twodisadvantageous features (1) when potential is first applied to suchcircuits the voltage immediately available for starting is lower thanthat of the supply circuit, and (2) for a short interval during thestarting period the heater of the thermionic electrode is surcharged andsaid filament carries almost twice its normal load.

The object of the present invention is to provide a gaseous electricdischarge device having thermionic electrodes and adapted to start andoperate on the 110 or 220 volt current sources of commerce. Anotherobject of the invention is to provide a simple starting and operatingcircuit for gaseous electric discharge devices having thermionicelectrodes. Still further objects and advantages attaching to the deviceand to its use and operation will be apparent to those skilled in theart from the following particular description and from the appendedclaims.

In the drawings accompanying and forming part of this specificationthree embodiments of the invention are shown, in which Fig. 1 is aschematic view of one embodiment of the invention and a circuittherefor;

Fig. 2 is a similar view of another embodiment and a circuit therefor,and

Fig. 3 is a similar view of still another embodiment and a circuittherefor.

Like numbers denote like parts in all the figures.

Referring to Fig. 1 of the drawings the new and novel gaseous electricdischarge device comprises a tubular container 1 having a gaseousatmosphere therein such as nitrogen, neon, or a mixture of argon andmercury. Four indirectly heated, uni-potential, thermionic electrodes 2,3, 4 and 5, such as the well known Hull cathode consisting of a metalshell, such as nickel, coated with electron emissive material, such asbarium "oxide, and having a tungsten heater filament therein, are sealedinto said container 1, two at each end thereof. Said electrodes 2 and 3,4 and 5, are electrically connected to each other by leads 14.and 15,respectively. Heater filaments 6, '7, 8 and 9 are provided for saidelectrodes 2, 3, 4 and 5 respectively. One end of each of said filaments7 and 9 is connected to said electrodes 3 and 5 respectively. Theopposite ends of said filaments? and 9 are connected to said filaments 6and 8 of said electrodes 2 and 4 through resistances 16 and 17respectively. Said filaments 6 and 8 are connected to each other throughresistance l3 and switch 10 and to the terminals 11 and 12 of analternating current source of commercial voltage, such as 110 or 220volts.

' In starting the device switch 10 is closed and current flows fromterminal 11, through the filament 6, the switch 10, the resistance 13,the filament 8 and hence back to the terminal 12. The currentconsumption of said resistance 13 is such that the electrodes 2 and 4are heated to their electron emitting temperature by filaments 6 and 8.When said electrodes 2 and 4 have reached such temperature the gaseouselectric discharge starts'between said electrodes 2 and 4 on the normalpotential of the source, such as 110 or 220 volts.

The discharge current then flows, on one hand, through the resistance16, the filament '7, the electrode 3 and thence to electrode 2 over lead14 and on 'the other hand through resistance 17, the filament 9, theelectrode 5 and thence to electrode 4 over lead 15. The dischargecurrent thus heats the filaments 7 and 9 which bring the electrodes 3and 5 to their electron emitting, discharge suppogting temperature.Where desired, the discharge is supported during the operation of thedevice by said electrodes 3 and 5 alone and the discharge is transferredfrom said electrodes 2 and 4 to said electrodes 3 and 5 by openingswitch 10.

Thus said electrodes 3 and 5 support the discharge only during theoperation of the device and when said electrodes 3 and -5 first startinto operation their electron emission is supplemented by that of saidelectrodes 2 and 4 to insure a safe and certain transference of thedischarge thereto. It is obvious that an electric discharge device asdescribed above having two sets of electrodes to support the discharge,one during the starting period and the other during the operatingperiod, has a longer life than a similar device having but one set ofelectrodes which support the discharge during both the starting and theoperating periods. Further, the external resistance essential in priordevices to absorb the excess potential after the starting of thedischarge is not necessary in electric discharge devices made inaccordance with the present invention, resistances 16 and 17 and thefilaments 7 and 9 are sufiicient for this purpose. Thus part of theenergy wasted in the ballast means of prior devices is utilized for theheating electrodes in the device of the present invention while abnormalloads on the heating filaments are avoided and the full line potentialis immediately available at the electrodes for purposes of starting. Itis apparent that where the resistance of the filaments '1 and 9 is of asuificiently high value the resistances 16 and 1'! are cut out ofcircuit, where desired, during the operation 01' the electric dischargedevice.

The embodiment of my invention shown in Fig. 2 has a slightly difierentcircuit than that shown in Fig. 1 and is designed to operate on a muchlower potential, 15 volts, for example, and is connected in series withother analogous devices.

Assuming that the potential drop between'the" electrodes is 11 volts theclosing of switch 10 sends the current through the filament 6, theresistance 2'7, the switch 10 and the filament 8. After the electrodes 2and 4 have been heated to an electron emitting discharge supporting temperature, an electric discharge is established between them on the linepotential. The filaments '7 and 9 are connected in series with saidelectrodes 2 and 4 and each of said filaments '1 and 9 consume twovolts, for example. When switch 10 is open circuited said electrodes 2and 4 are cut out of circuit and the full line potential is appliedacross said electrodes 3 and 5 which starts an electric dischargebetween said last named electrodes. It is obvious that a multiplicity oisuch devices are adapted to be connected to each I at an operatingtemperature.

other either in series or in parallel as desired.

The embodiment of the invention illustrated in Fig. 3 has still adifferent circuit than that shown in Figs. 1 and 2. Electrodes 2 and 4,which are the starting electrodes, are separated a distance equal to orslightly less than the distance at which a discharge will start betweenthem on the line potential when said electrodes are The electrodes 3 and5 are separated a greater distance than said electrodes 2 and 4 and areconnected to said electrodes 2 and 4 through resistances 18 and 22respectively. Switches 19 and 20 are provided to break the electricalconnection between said electrodes 2 and 3, 4 and 5 respectively. Whenthe device is started into operation switches 10, 18 and 20 are closedand current fiows through the heater filaments 6 and 8 of saidelectrodes 2 and 4 respectively. Assoon as said electrodes 2 and 4 havebeen heated to an electron emitting discharge supporting temperature byfilaments 6 and 8 respectively, an arc discharge takes place betweensaid electrodes 2 and 4 on the line voltage. The discharge current thenflows through resistances 16, 17, 18 and 22 and filaments 7 and 9 whichheat the electrodes 3 and 5 to an electron emitting discharge supportingtemperature and said electrodes 3 and 5 then participate in supportingthe discharge in the device. The are current between electrodes 2 and 4is then greater than that between electrodes 3 and 5 and the potentialdrop' between said electrodes 3 and 5 is obviously larger than thatbetween said electrodes 2 and 4. The resistances 18 and 22 are rentbetween said electrodes 2 and 4 decreases while that between saidelectrodes 3 and 5 intrated in Fig. 3 makes possible an increase in theuseful length of tubular devices such as that illustrated in Fig. 1 oran increase'in the diameter oi. globular devices such as thatillustrated in Fig. 2 without increasing the voltage required to startthe discharge in such devices. f

The above described electric discharge devices may be changed in variousrespects without departureirom the broad spirit and scope of theinvention, for example, electrodes having one or more electricallyinsulated heat radiators are used, where desired.

What I claim as new and desire to secure by Letters Patent 0! the UnitedStates is 1. An electric discharge device comprising a container, aplurality of electrodes sealed therein, a gaseous atmosphere therein anda heater means for each of said electrodes, said electrodes beingelectron emitting, some of said electrodes supporting the dischargeduring the starting period and some of said electrodes supporting thedischarge during the operating period, said first named electrodes beingseparated a distance less than the striking distance of said discharge.

2. An electric discharge device comprising a container, a plurality ofelectrodes sealed therein, a gaseous atmosphere therein and a heatermeans for each of said electrodes, said electrodes being electronemitting when heated, some of said electrodes supporting the dischargeduring the starting period and some of said electrodes supporting thedischarge during the operating period,sa id first named electrodes beingseparated a distance less than the striking distance of said discharge,

the other electrodes being separated a greater distance than said firstnamed electrodes.

3. An electric discharge device comprising a container, a plurality ofelectrodes sealed therein, a gaseous atmosphere therein and a heatermeans for each of said electrodes, said container having a bulbshape-and said electrodes being centrally located therein and electronemitting when heated, some oi said electrodes supporting the dischargeduring the starting period and some of said electrodes supporting thedischarge during the operating period, said first named electrodes beingseparated a distance less than the striking distance of said discharge,the other electrodes being separated a greater distance than said first

